An aircraft that is parked at a gate is not only delaying passengers, but is also not earning revenue from the transport of passengers or crew. Considering the value of passenger inconvenience and the capital costs of aircraft, delays may represent a significant expense for airlines. Not only can even a few extra minutes an aircraft is on the ground reduce airline revenues, but this additional time may adversely affect an airline's daily schedule. Currently, an aircraft is required to maneuver under the power of one or more of its main engines into a parking location at a terminal and park in a “nose-in” orientation, with the aircraft longest axis located perpendicular to a terminal building or gate, or, alternatively, an aircraft is towed into a parking location in this orientation. Typically, once the aircraft's engines have been shut down, a single passenger boarding or loading bridge is moved into place to align with and connect to an aircraft's forward door so that passengers may leave the aircraft and walk to the terminal gate. Ground service vehicles may also then approach the aircraft to provide various aircraft gate services, including transferring baggage and cargo, supplying fresh water and catering supplies, removing waste water, and the like. When the aircraft is ready for departure, passengers are boarded through the loading bridge, ground service vehicles leave the vicinity of the aircraft after service is completed, and a tug or tow vehicle is attached to the aircraft when pushback clearance is received. The aircraft is pushed in reverse by the tug to a location where the aircraft can start one or more of its engines and move in a forward direction to a takeoff runway.
The airline industry has recognized the importance of efficiently unloading and loading passengers and providing the requisite servicing of aircraft so aircraft can be turned around as quickly as possible to maintain the airline's flight schedule and achieve the highest aircraft utilization possible. Moreover, an airline's revenue and potential profits may be increased the less time an aircraft is on the ground and the more time it is in flight transporting passengers and crew. Every minute by which an aircraft's turnaround time is reduced increases time the aircraft may be in flight, in turn minimizing passenger inconvenience due to delays and increasing airline revenue. While estimates of the specific amount of airline cost savings that may be achieved for each minute aircraft turnaround time is reduced may vary, it is generally acknowledged that these savings are potentially substantial.
Ideally, aircraft should be able to park at any airport so that transfer of passengers and baggage and servicing of the aircraft may be accomplished in a manner that minimizes turnaround times and maximizes ease of operation for a pilot taxiing into a terminal gate. This is not always the reality, however, and the ease and efficiency of aircraft parking and servicing and, therefore, turnaround time and the predictability of turnaround time vary widely. Improvements in aircraft gate parking, servicing, and turnaround efficiency and predictability that reduce airlines' operating costs continue to be proposed. While proposed approaches to improving the efficiency of aircraft parking, passenger transfer, and aircraft servicing have had some success, additional reductions in the time an aircraft spends on the ground have remained elusive. Consequently, current predictions of aircraft turnaround time are not as accurate as desired.
Airport terminal parking spaces for aircraft must be designed to ensure that a minimum apron space is available around each aircraft. This minimum space must accommodate not only passenger loading bridges, but also ground service vehicles and equipment, while satisfying Federal Aviation Administration (FAA) and corresponding international regulatory agency requirements. Aircraft wing tip clearance requirements, in particular, must be strictly observed to avoid contact between adjacent aircraft during taxi-in or tow-in and pushback. The aircraft parking method and system described by Hutton in U.S. Pat. No. 6,914,542, for example, focuses on maintaining adequate wing tip clearance for different aircraft types parking at an airport terminal equipped with a single loading bridge for reach aircraft.
To increase the efficiency with which passengers can be moved out of and into aircraft, especially very large aircraft that have multiple entrances and passenger levels, some airport terminal gates have two loading bridges available for such aircraft that can be extended horizontally and/or vertically to service aircraft using two different doors simultaneously. In one arrangement, an “over-the-wing” bridge is designed to be connected to an aircraft's rear door while a conventional loading bridge is connected to a forward door to provide two passenger loading bridges for Airbus 319-321, Boeing 737, and similar aircraft when the aircraft is parked perpendicular to an airport terminal gate. Such an arrangement with over-the-wing loading bridges is described in U.S. Pat. No. 7,039,978 to Hutton. Over-the-wing loading bridges are available from FMT Aircraft Gate Support Systems of Sweden and other suppliers and have been installed at many airports. This type of passenger loading bridge must be designed to clear the aircraft wing height, also allowing for the height of winglets. In addition, maneuvering the bridge over the aircraft wing into place to accurately align with and connect to an aircraft rear door may take more time than maneuvering a bridge that does not have to be moved into place over an aircraft wing to align with an aircraft door located rear of a wing. Although intended to improve passenger transfer efficiency, the additional time that may be required to extend, connect, disconnect, and retract an over-the-wing loading bridge may increase, rather than decrease, turnaround time. Even when over-the-wing loading bridges are designed to include sensors and to be moved into and out of place automatically to minimize time required for connection and disconnection, the height of such loading bridges above an aircraft wing requires careful monitoring as they are maneuvered into place above an aircraft wing. Over-the-wing loading bridges have been involved in accidents, including at least one in which an aircraft wing was hit and damaged when the loading bridge collapsed during its extension to connect with the aircraft aft door. As a result of the possibility of aircraft wing damage and for other reasons that appear to be related to cost-effectiveness, use of over-the-wing loading bridges is not as widespread as initially hoped, at least in the United States.
Another type of dual passenger loading bridge system is described and shown in U.S. Pat. Nos. 7,275,715 and 7,614,585, assigned to Boeing. This complex system, which is also designed to be used with an aircraft parked perpendicular to a terminal building in a “nose-in” orientation, may also include structure for handling baggage and cargo and for providing some aircraft utilities. The Boeing system has an arrangement of lateral bridge extensions that are required to connect one or more main bridge sections to doors on one or both sides of the aircraft. Although the intent of a dual passenger loading system, such as the Boeing system and the over-the-wing type of system, is to allow faster passenger egress and ingress, the practice when dual loading bridges are available has been to use one loading bridge for first and business class passengers and the other for economy class passengers.
For a number of years, aircraft utilities have been attached to passenger loading bridges and connected to aircraft to supply, for example, electric power, temperature and humidity-conditioned air, and compressed air to an aircraft at a gate during the turnaround process. In U.S. Pat. No. 3,521,316, Adams et al describes providing these utilities to an aircraft concurrently with passenger boarding. The service transport unit described by McEntire et al in U.S. Pat. No. 5,149,017 includes a utility bundle attached to and designed to extend and retract with a passenger loading bridge, and the loading bridge-mounted heat exchanger with extensible supply and return lines described by Shepheard in U.S. Pat. No. 4,620,339 provide utilities to a parked aircraft. The foregoing arrangements avoid the need for providing such aircraft services by separate conduits or connections not associated with a landing bridge and reduce the numbers of such structures in a terminal gate area. U.S. Pat. No. 5,505,237 to Magne discloses a partially or completely automated aircraft refueling installation integrated into a passenger loading bridge to eliminate or reduce the need for fuel vehicles in a gate area. Improving aircraft gate turnaround by increasing the efficiency of gate services is not a stated goal of the systems in these patents.
The loading bridge arrangements known in the art, including those described above, whether or not aircraft utilities are connected with the loading bridge, are all premised on providing connections with aircraft that are parked in a “nose-in” orientation relative to an airport terminal building so that the longest axial dimension of the aircraft is oriented perpendicular to the terminal building. Consequently, passenger loading bridges are constructed to that they can be extended between the terminal and the aircraft at an angle that will align with an aircraft door, usually a forward door on a side of the aircraft closest to the loading bridge, to provide an effective connection. Many passenger loading bridges have rotundas or the like that can rotate and thus facilitate the connection between a loading bridge and an aircraft door, but alignment may still pose challenges.
Parking an aircraft so that the longest axial dimension is parallel to a terminal building avoids the need for an over-the-wing type of loading bridge and simplifies the extension and alignment of dual passenger loading bridges with aircraft doors. At airport terminals designed to accommodate wide body aircraft, this type of arrangement may work very effectively to improve aircraft gate efficiency and minimize turnaround time. Loading bridges can be easily aligned and directly connected with both forward and rear doors on a side of the aircraft facing the terminal. Required minimum clearances can also be maintained. Not every airport has gates designed to accommodate wide body aircraft, however, and the gate servicing efficiencies possible when aircraft are parked parallel to a terminal gate cannot be realized because aircraft cannot be parked in a parallel orientation and maintain required clearances.
A need exists, therefore, for an improved method for parking and servicing aircraft at airport terminal gates in an alternative orientation that achieves the benefits and time savings possible when an aircraft is parked in a parallel orientation while conforming to minimum parking clearances for airport parking spaces designed to accommodate narrow body and similarly sized aircraft. A need further exists for a method for parking aircraft in an optimum parking orientation within gate clearances that facilitates alignment and connection of passenger loading bridges with aircraft doors located rear of an aircraft wing that overcomes the disadvantages associated with aligning and connecting over-the-wing loading bridges to rear aircraft doors.